I would like to but i dont know which code i can provide. The combobox is filled by a SQL resquest. The setting of my combobox is ajusted with the properties tab.

If i press manually to access the list, everything is there in both OS. If i wrote in the combobox, than a list is made with the Suggest setting. The only difference is the fact that the list is not complete with XP as is it with win7.

This code would be important. Also you mention settings adjusted by properties. What are the settings you adjust and then verify that you do not make any changes to the properties of the control within other methods of your form, if you do, include those changes.

Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
- Combine task lists, docs, spreadsheets, and chat in one
- View and edit from mobile/offline
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I unfortunately cannot replicate your issue using the ComboBox and Windows XP. However, perhaps it is the mechanism internal to the combobox that is causing you grief. See if this test project gives you any better behaviour:

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